Latham said his client was forced to perform oral sex at school. "He described it in a way that he was a victim of sexual assault," he said.

Latham said people with narcissistic personality disorder had problems empathising with others and sought constant praise.

"When that breaks down the consequence is dramatic," Latham told the court.

Jutting's penchant for torture, coupled with substance abuse and alcoholism, meant that his behaviour was "substantially impaired" when he committed the gruesome murders of Sumarti Ningsih, 23, and Seneng Mujiasih, 26.

He tortured Ningsih for three days before killing her and cramming the body inside a suitcase.

Police found Mujiasih lying on the floor with grievous wounds on her body.

When asked by Judge Michael Stuart-Moore whether voluntary intoxication constituted a defence, Latham said the drive to take drugs and alcohol was "extremely difficult to resist".